Sorry for the confusion. Unfortunately this is sometimes what happens when the person posting isn't familiar with the terminology.
I posted this with the title dealing with analog prior to wording my entire post. Unfortunately, as i started typing I tried to keep my questions limited and didn't add items that dealt with analog to digital conversion. What I have however in this project is something that is analog communicating with an A/D converter using an RS232 port. I'll explain below in detail with the hopes that it makes sense.
My friend has a hand grip that is used to measure force. It is not digital and it has an analog readout. A long time ago, the innards of the hand grip were altered slightly so that the hand grip could communicate the force results to a computer. Three wires were connected to the hand grip internally, and these wires were attached to an RS232 cable. This RS232 cable attaches to an RS232 port on a small box that houses, among other things, an A/D converter. This box has an output RS232 port that you attach to an RS232 port on a computer, allowing the findings from the hand grip to be communicated to the computer and then analyzed.
A few things have happened since then and recently. RS232 ports on computers have become rarer and rarer, RS232 to USB converters are very hit and miss (at least with what we are using currently) with almost all of them being "miss", and most importantly, the box is failing and the company that built it is out of business. I have programming experience (have built some applications in Visual Foxpro) but no hardware experience (probably can tell by my posts). I am trying to see if this is something that I can help out with, as there is time but limited budget. I remember when I first started in Foxpro and didn't even know what a database was. I learned a lot over time and now have become pretty decent with it. I'm hoping that this will happen with hardware too (I'm starting out in pretty much the same place). I am a little slower these days but as I said time is not the issue right now.
I thought the Arduino (and possibly Rasberry PI) would work well in this situation, so I have purchased both and spent some time reading about them over the past week or so. However, I have only gotten so far with this and thought I could post on one of these forums and get some help. The links so far have proven to be really good, especially the RS232 board for the Arduino. However, I don't see how the virtual USB would help in this (this of course is probably due to my post not being clear previously).
What I would like to do is the following:
Connect the hand grip through the already attached RS232 cable to the Arduino Uno. Have the Uno convert the analog hand grip readings (as the hand grip is being used) to digital, and then communicate that directly to a computer attached to the Uno. Right now, this is done using a box that is failing and the box communicates to the computer using an RS232 port. I would prefer to have the Uno communicate using USB, something that is more recent and is on every computer. BTW, I saw a link above for an UNO with an SD card attached but I would prefer not to have the separate step of having the data stored on an SD card and then having to attach the card to a computer.
If possible (not necessary but would be nice) to rewire the innards of the hand grip to make it into a USB connection rather than a RS232 connection. Right now as mentioned above there are three wires going from the hand grip to an RS232 cable. I would like to change the wiring to make it a USB connection. Then use the hand grip as described in the previous option.
I hope the above sheds more light on what I'm looking at. I really appreciate the help so far and hopefully you guys/gals can help a bit more with the above.